I have dual batteries. The are both deep cycle marine duralast's. But if we beach and shut the boat off I turn the perko on to battery #2 for the stereo and the battery dies after 2 or 3 hours. I was thinking of upgrading to optima's. Is that a good choice or is there something better out there? I don't want to drop $600 each on the stingers even though I am sure they would outlast any battery out there. Just to much money...